Study Questions:

What is the association between hypertension during pregnancy as a risk factor for cardiomyopathy?

Methods:

This was a large cohort study of 1,075,763 women in Denmark (1978-2012) with at least one pregnancy (live birth or still birth) with or without a diagnosis of hypertensive disorders of pregnancy (HDP: gestational hypertension, moderate preeclampsia, and severe preeclampsia). Patients were excluded if they carried a diagnosis of cardiovascular disease, diabetes mellitus (more than 1 month before delivery), or pregnancies with gestational length <20 weeks. The primary outcome was cardiomyopathy >5 months after delivery (outside the peripartum period), up to 34 years 7 months for follow-up.

Results:

Of the cohort study of pregnancies, 12, 974 were complicated by severe preeclampsia, 44,711 with moderate preeclampsia, and 18,423 with gestational hypertension. A total of 1,577 women (mean age, 48.5 years at cardiomyopathy diagnosis; 2.6% with multiple pregnancies) developed cardiomyopathy. Comparing rates of cardiomyopathy for women with a history of HDP compared to normotensive pregnancies yielded hazard ratios of 2.2 (95% confidence interval [CI], 1.50-3.23) for severe preeclampsia, 1.89 (95% CI, 1.55-2.32) for moderate preeclampsia, and 2.06 (95% CI, 1.55-2.82) for gestational hypertension. These increases in women with a history of HDP lasted for >5 years after the latest pregnancy. Based on these data, rates were 14.6-17.3 cases/100,000 person- years).

Conclusions:

Hypertensive disorders of pregnancy are associated with an increased risk of cardiomyopathy >5 months after delivery.

Perspective:

Although hypertensive disorders of pregnancy are associated with an increased risk of cardiomyopathy, the event itself remains rare. The diagnosis of cardiomyopathy should still be considered in women with these risk factors and clinical symptoms, even through the peripartum period.